US8959342B2 - Communication apparatus - Google Patents
Communication apparatus Download PDFInfo
- Publication number
- US8959342B2 US8959342B2 US12/964,041 US96404110A US8959342B2 US 8959342 B2 US8959342 B2 US 8959342B2 US 96404110 A US96404110 A US 96404110A US 8959342 B2 US8959342 B2 US 8959342B2
- Authority
- US
- United States
- Prior art keywords
- authentication
- rtt test
- authentication processing
- processing
- prior
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related, expires
Links
Images
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L9/00—Cryptographic mechanisms or cryptographic arrangements for secret or secure communications; Network security protocols
- H04L9/08—Key distribution or management, e.g. generation, sharing or updating, of cryptographic keys or passwords
- H04L9/0816—Key establishment, i.e. cryptographic processes or cryptographic protocols whereby a shared secret becomes available to two or more parties, for subsequent use
- H04L9/0838—Key agreement, i.e. key establishment technique in which a shared key is derived by parties as a function of information contributed by, or associated with, each of these
- H04L9/0841—Key agreement, i.e. key establishment technique in which a shared key is derived by parties as a function of information contributed by, or associated with, each of these involving Diffie-Hellman or related key agreement protocols
- H04L9/0844—Key agreement, i.e. key establishment technique in which a shared key is derived by parties as a function of information contributed by, or associated with, each of these involving Diffie-Hellman or related key agreement protocols with user authentication or key authentication, e.g. ElGamal, MTI, MQV-Menezes-Qu-Vanstone protocol or Diffie-Hellman protocols using implicitly-certified keys
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L9/00—Cryptographic mechanisms or cryptographic arrangements for secret or secure communications; Network security protocols
- H04L9/32—Cryptographic mechanisms or cryptographic arrangements for secret or secure communications; Network security protocols including means for verifying the identity or authority of a user of the system or for message authentication, e.g. authorization, entity authentication, data integrity or data verification, non-repudiation, key authentication or verification of credentials
- H04L9/3271—Cryptographic mechanisms or cryptographic arrangements for secret or secure communications; Network security protocols including means for verifying the identity or authority of a user of the system or for message authentication, e.g. authorization, entity authentication, data integrity or data verification, non-repudiation, key authentication or verification of credentials using challenge-response
Definitions
- the present invention relates to a technology of a Round Trip Time (RTT) test to be performed for authenticating an apparatus in a communication system.
- RTT Round Trip Time
- a technology of a Round Trip Time (RTT) test to be performed for authenticating an apparatus has been known in a system including a plurality of apparatuses connected over a network.
- a source that is an apparatus transmitting a content authenticates an apparatus that is a destination of the content and transmits the content to the authenticated apparatus.
- DTCP Volume 1 supplement F DTCP 1394 Additional Localization D Informational Version
- P. 4-9 [online], Jun. 15, 2007, Digital Transmission Licensing Administrator (DTLA), [searched on Dec. 22, 2009], the Internet (http://www.dtcp.com/data/info 20070615 DTCP V1SF 1p 0.pdf)).
- the source when receiving an authentication request from another apparatus, the source checks whether the apparatus having issued the authentication request has already passed an RTT test (including measuring an RTT and determining whether the RTT is within a predetermined period of time or not). If it has passed, the processing moves to the authentication processing. If not, the source performs an RTT test on the apparatus having issued the authentication request. Only if the apparatus passes the RTT test, the processing moves to authentication processing. Thus, the range of transmission of the content from the source can be limited to a local range.
- an RTT test may be performed on the apparatus having issued the authentication request.
- one apparatus may require authentication processing for each channel used for transferring a content for the apparatus configuration or may need independent encoding for each content, authentication requests may be serially issued to the source for a plurality of contents to be received from the source. Then, the following problems may occur.
- a communication apparatus that performs data communication with a communication device, the communication apparatus including an authentication processing portion that performs authentication processing including an RTT test on authentication requests received from the unauthenticated communication devices, and a data communication portion that performs the data communication with the communication device authenticated by the authentication processing portion.
- the authentication processing portion does not perform the RTT test in the authentication processing but waits for the completion of the RTT test in the other authentication processing and, if the result of the RTT test in the other authentication processing is pass, the authentication processing portion omits the RTT test in the authentication processing and uses the result of the RTT test in the other authentication processing as the result of the RTT test in the authentication processing.
- the authentication processing portion may not perform the RTT test in the authentication processing but waits for the completion of the RTT test in the other authentication processing and, if the result of the RTT test in the other authentication processing is not pass, the authentication processing portion may perform the RTT test in the authentication processing.
- the authentication processing may include first processing for sharing an authentication key with the communication device having issued the target authentication request, the RTT test, and second processing of transmitting an exchange key encoded by using the authentication key to the communication device.
- the communication portion may perform the encoded data communication by using the exchange key with the communication device to which the exchange key has been transmitted. If, in authentication processing on the authentication requests, after performing the first processing, the RTT test is being performed in other authentication processing on another authentication request originating from the same communication device as the authentication request to undergo the authentication processing, the authentication processing portion may not perform the RTT test in the authentication processing but waits for the completion of the RTT test in the other authentication processing and, if the result of the RTT test in the other authentication processing is pass, the authentication processing portion may perform the second processing.
- the authentication processing portion may not perform the RTT test in the authentication processing but waits for the completion of the RTT test in the other authentication processing and, if the result of the RTT test in the other authentication processing is not pass, the authentication processing portion may perform the RTT test in the authentication processing, if the result of the RTT test is pass, the authentication processing portion performs the second processing, and if the result of the RTT test in the other authentication processing is not pass, the authentication processing portion may not perform the second processing.
- the authentication processing portion waits for the completion of the RTT test in the other authentication processing and, if the result of the RTT test in the other authentication processing is pass, the result of the RTT test in the other authentication processing is used as the result of the RTT test in the authentication processing.
- redundant implementation of an RTT test on one communication device can be prevented if the communication device has passed the RTT test. Since it can eliminate the necessity for sequentially performing entire authentication processing on authentication requests, delay of authentication processing can be prevented.
- a communication apparatus that performs data communication with a communication device, the communication apparatus comprising:
- an authentication processing portion that performs authentication processing including an RTT test on authentication requests received from the unauthenticated communication devices
- the authentication processing portion does not perform the RTT test in the authentication processing and uses the result of the RTT test in the other authentication processing as the result of the RTT test in the authentication processing.
- the authentication processing may include first processing for sharing an authentication key with the communication device having issued the target authentication request, the RTT test, and second processing of transmitting an exchange key encoded by using the authentication key to the communication device.
- the communication portion may perform the encoded data communication by using the exchange key with the communication device to which the exchange key has been transmitted. If, in authentication processing on the authentication requests, after performing the first processing, the RTT test is being performed in other authentication processing on another authentication request originating from the same communication device as the authentication request to undergo the authentication processing, the authentication processing portion may not perform the RTT test in the authentication processing but wait for the completion of the RTT test in the other authentication processing and, if the result of the RTT test in the other authentication processing is pass, the authentication processing portion may perform the second processing. If the result of the RTT test in the other authentication processing is not pass, the authentication processing portion may not perform the second processing.
- the authentication processing portion may not perform the RTT test in the authentication processing but uses the result of the RTT test in the other authentication processing as the result of the RTT test in the authentication processing.
- redundant implementation of an RTT test on the same communication device can be prevented. Since it can eliminate the necessity for sequentially performing entire authentication processing on authentication requests, delay of authentication processing can be prevented.
- the communication apparatus and the communication device may perform data communication based on the IEEE1394 standard, and the authentication processing may perform authentication based on the DTCP standard.
- the communication portion may transmit data of an audio/visual (AV) content in the data communication.
- AV audio/visual
- delay of authentication processing can be prevented, and redundant RTT tests on the same apparatus can be prevented.
- FIG. 1 is a block diagram illustrating a configuration of an AV system according to an embodiment of the present invention
- FIG. 2 is a block diagram illustrating a functional configuration of the AV apparatus according to the embodiment of the present invention
- FIG. 3 illustrates sequences of authentication operations
- FIGS. 4A and 4B are flowcharts illustrating the authentication processing according to the embodiment of the present invention.
- FIG. 5 is a flowchart illustrating individual request authentication processing according to the embodiment of the present invention.
- FIG. 1 illustrates a configuration of an AV system according to the embodiment.
- the AV system illustrated in FIG. 1 includes a plurality of AV apparatuses 1 connected via a bus 2 based on the IEEE 1394 standard.
- the each of the AV apparatuses 1 includes a bus control portion 10 , a CPU 11 , a memory 12 , an AV device 13 , and an input device 14 .
- the AV device 13 receives input of and/or outputs at least one of audio and visual signals.
- the AV device 13 may be a display, an audio player, a video player, a television receiver, a radio receiver, an audio output device or the like.
- FIG. 2 illustrates a functional configuration of the AV apparatus 1 .
- An authentication processing portion 21 and AV control portion 22 illustrated in FIG. 2 are functions implemented by the execution of programs stored in the memory 12 by the CPU 11 .
- the bus control portion 10 includes a transmitter/receiver 101 that inputs and/or receives the output of a signal to/from the bus 2 and an encoder/decoder 102 that encodes/decodes content data transmitted from the AV device 13 to another device via the bus 2 or received from another device via the bus 2 .
- the AV control portion 22 controls an operation by the AV apparatus 1 in accordance with a user operation or a command received from another AV apparatus 1 through the bus control portion 10 .
- the authentication processing portion 21 controls authentication operations between a source and a sink.
- the authentication operations between a source and a sink are based on DTCP disclosed in “DTCP Volume 1 supplement F DTCP 1394 Additional Localization D (Informational Version)” above.
- FIG. 3 illustrates overall sequences of basic authentication operations between a source and a sink.
- a sink first of all issues to a source an authentication and key exchange (AKE) request for authentication and key exchange including a certificate.
- AKE authentication and key exchange
- the source here refers to an AV apparatus 1 that transmits content data to another AV apparatus
- the sink refers to an AV apparatus 1 that receives content data from the source AV apparatus 1 .
- the source If the validity of an AKE request originator is authenticated by using the certificate, the source performs challenge-response sequences of exchanging predetermined information through a challenge and a response with the AKE request originator and generating a common authentication key between the source and the AKE request originator.
- an RTT test is performed.
- the source first exchanges a predetermined command/response with the sink for preparation for the RTT test.
- an RTT test command is transmitted to the sink.
- a reception response transmitted from the sink is received as the response.
- the RTT is measured and whether the measured RTT exceeds a predetermined limit time or not is determined. If not, it is determined that the sink has passed the RTT test.
- the exchange key encoded by using the authentication key is transmitted to the AKE request originator.
- the authentication processing to be performed by the authentication processing portion 21 in the source will be described below.
- FIG. 4A illustrates a routine of the authentication processing.
- the processing first monitors the reception of an AKE request (step 400 ).
- the processing stores the identification number given to the received AKE request along with an identifier such as the node number of the originator of the AKE request in a request table as illustrated in FIG. 4B (step 402 ).
- an identification number given to an AKE request, an identifier of the originator of the AKE request, a processing flag, and an RTT test pass flag may be registered with an entry (row in FIG. 4B ) in the request table.
- the initial values of the processing flag and RTT test pass flag are “OFF”.
- step 404 individual request authentication processing is started on the received AKE request assigned as a target request.
- the processing then returns to monitoring in step 402 .
- FIG. 5 illustrates a routine of the individual request authentication processing to be started in step 404 of the authentication processing.
- the processing first performs the authentication operations up to the challenge-response sequences on the originator of the AKE request assigned as the target request (step 500 ).
- step 502 Whether an RTT is measurable or not is checked. If not, the exchange key encoded with the authentication key shared in the challenge-response sequences performed to and from the originator is transmitted to the originator of the AKE request assigned as the target request (step 524 ). The entry having the identification number of the AKE request assigned as the target request is deleted from the request table (step 526 ), and the individual request authentication processing ends.
- the sink being the originator of the AKE request assigned as the target request checks whether the sink has already been registered with an RTT register that stores a sink that had passed an RTT test or not (step 504 ).
- step 504 If not (step 504 ), whether any other entry that stores the same originator as the originator registered with the entry having the identification number of the AKE request assigned as the target request in the request table in FIG. 4B and has “ON” as the value of the RTT test pass flag exists in the request table or not is checked (step 506 ).
- step 506 whether any other entry that stores the same originator as the originator registered with the entry having the identification number of the AKE request assigned as the target request in the request table and has “ON” as the value of the processing flag exists in the request table or not is further checked (step 508 ). If not, the processing moves to step 510 .
- step 510 the processing flag of the entry having the identification number of the AKE request assigned as the target request in the request table is set to “ON”.
- an RTT test is performed on the originator of the AKE request assigned as the target request up to 1024 times until the originator passes the RTT test (step 512 - 516 and 532 - 534 ).
- the preparation for the RTT test is implemented and the RTT test is set up between the source and the sink being the originator of the AKE request assigned as the target request.
- the an RTT test command is transmitted to the sink, and a reception response transmitted from the sink is received as the response.
- the RTT is measured, and whether the measured RTT does not exceed a predetermined time limit or not is determined. If not, it is determined that the sink has passed the RTT test.
- the preparation for the RTT tests has already been completed.
- an RTT test command is transmitted to the sink.
- a reception response transmitted from the sink is received as the response.
- the RTT is measured, and whether the measured RTT does not exceed a predetermined time limit or not is determined. If not, it is determined that the sink has passed the RTT test.
- the processing flag in the entry having the identification number of the AKE request assigned as the target request in the request table is set to “OFF” (step 536 ).
- the entry having the identification number of the AKE request assigned as the target request is deleted from the request table (step 526 ), and the individual request authentication processing ends.
- the sink passes the RTT test before 1024 implementations of the RTT test on the other hand (step 516 ).
- the RTT test pass flag in the entry having the identification number of the AKE request assigned as the target request in the request table is set to “ON” (step 518 ).
- the processing flag in the entry having the identification number of the AKE request assigned as the target request in the request table is set to “OFF” (step 520 ).
- the registration effective period of the sink being the originator of the AKE request assigned as the target request is set to 40 hours, and the sink being the originator of the AKE request assigned as the target request is registered with the RTT register (step 522 ).
- the sink registered with the RTT register is deleted from the RTT register after the expiration of the registration effective period.
- the exchange key encoded with the authentication key shared in the challenge-response sequences performed to and from the originator is transmitted to the originator of the AKE request assigned as the target request (step 524 ).
- the entry having the identification number of the AKE request assigned as the target request is deleted from the request table (step 526 ). Then, the individual request authentication processing ends.
- step 508 If it is determined in step 508 that another entry that stores the same originator as the originator registered with the entry having the identification number of the AKE request assigned as the target request in the request table and has “ON” as the value of the processing flag exists in the request table, an RTT test is being performed in other individual request authentication processing on the originator of the AKE request assigned as the target request.
- the source waits for the setting of the processing flag of the other individual request authentication processing existing to “OFF” (step 528 ). Then, whether the RTT test pass flag in the entry existing is “ON” or not is checked (step 530 ).
- the RTT test pass flag is ON (step 530 ), it means that the RTT test on the originator of the AKE request assigned as the target request has ended as a result of the pass in the other individual request authentication processing. Thus, the result is used as the result of the RTT test on its individual request authentication processing, and the RTT test is not performed.
- the exchange key encoded with the authentication key shared in the challenge-response sequences performed to and from the originator is transmitted to the originator of the AKE request assigned as the target request (step 524 ).
- the entry having the identification number of the AKE request assigned as the target request is deleted from the request table (step 526 ), and the individual request authentication processing ends.
- step 530 If the RTT test pass flag is not “ON” (step 530 ) on the other hand, the processing moves to step 510 described above. However, if the RTT test pass flag is not “ON”, the entry having the identification number of the AKE request assigned as the target request may be deleted directly from request table (step 526 ) as indicated by the broken line in FIG. 5 , and the individual request authentication processing may end.
- step 506 If it is determined in step 506 that another entry in the request table that stores the same originator as the originator registered with the entry having the identification number of the AKE request assigned as the target request in the request table and has “ON” as the value of the RTT test pass flag exists in the request table, it means that the RTT test on the originator of the AKE request assigned as the target request has already ended as a result of the pass in the other individual request authentication processing. Thus, the result is used as the result of the RTT test on its individual request authentication processing, and the RTT test is not performed.
- the source transmits the exchange key encoded with the authentication key shared in the challenge-response sequences performed to and from the originator to the originator of the AKE request assigned as the target request (step 524 ).
- the entry having the identification number of the AKE request assigned as the target request is deleted from the request table (step 526 ), and the individual request authentication processing ends.
- step 504 if it is determined in step 504 that the sink being the originator of the AKE request assigned as the target request has already been registered with the RTT register, it means that the sink of the originator of the AKE request assigned as the target request has already been authenticated.
- the exchange key encoded with the authentication key shared in the challenge-response sequences performed to and from the originator is transmitted to the originator of the AKE request assigned as the target request (step 524 ).
- the entry having the identification number of the AKE request assigned as the target request is deleted from the request table (step 526 ), and the individual request authentication processing ends.
- the authentication processing and individual request authentication processing to be performed by the authentication processing portion 21 have been described above.
- the exchange key exchanged with the AKE request originator is set to the encoder/decoder 102 in the bus control portion 10 in the source.
- the encoder/decoder 102 encodes the content data received from the AV apparatus 1 and to be transmitted through the transmitter/receiver 101 with the cryptographic key acquired by using the exchange key transmitted to the destination sink of the content data.
- the sink having received the exchange key from the source sets the exchange key to the encoder/decoder 102 .
- the encoder/decoder 102 decodes the content data received from the source with the cryptographic key acquired by using the exchange key received from the source of the origin of the content data and outputs the decoded data.
- received AKE requests are processed in parallel in individual request authentication processing started for the AKE requests.
- an RTT test on the AKE request from the same originator as the AKE request being processed is being performed in other individual request authentication processing, the RTT test is not performed but the processing waits for the end of the RTT test in the other individual request authentication processing. If the corresponding sink passes the RTT test in the other individual request authentication processing, the result of the RTT test in the other individual request authentication processing is used as the result of the RTT test in the individual request authentication processing. Then, it is determined that the sink has passed the RTT test for the AKE request being processed, and the authentication processing advances without performing the RTT test.
- the entry having the identification number of the AKE request assigned as the target request may be deleted directly from request table (step 526 ) as indicated by the broken line in FIG. 5 , and the individual request authentication processing may end, as in step 530 .
- the RTT test on the AKE request from the same originator as the AKE request being processed is performed in other individual request authentication processing, the result of the RTT test in other individual request authentication processing may be used as the result of the RTT test in the individual request authentication processing whether the result of the RTT test is pass or fail. Therefore, further implementation of the RTT test on the sink having already completed the RTT test can be prevented.
Abstract
Description
Claims (18)
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JPJP2010-006750 | 2010-01-15 | ||
JP2010006750A JP2011146970A (en) | 2010-01-15 | 2010-01-15 | Communication apparatus |
JP2010-006750 | 2010-01-15 |
Publications (2)
Publication Number | Publication Date |
---|---|
US20110179276A1 US20110179276A1 (en) | 2011-07-21 |
US8959342B2 true US8959342B2 (en) | 2015-02-17 |
Family
ID=44278418
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US12/964,041 Expired - Fee Related US8959342B2 (en) | 2010-01-15 | 2010-12-09 | Communication apparatus |
Country Status (2)
Country | Link |
---|---|
US (1) | US8959342B2 (en) |
JP (1) | JP2011146970A (en) |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP5652036B2 (en) | 2010-07-29 | 2015-01-14 | ソニー株式会社 | COMMUNICATION SYSTEM, COMMUNICATION DEVICE, COMMUNICATION METHOD, AND COMPUTER PROGRAM |
US20140244956A1 (en) * | 2013-02-26 | 2014-08-28 | Kabushiki Kaisha Toshiba | Storage system in which fictitious information is prevented |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7058414B1 (en) * | 2000-05-26 | 2006-06-06 | Freescale Semiconductor, Inc. | Method and system for enabling device functions based on distance information |
US20070058559A1 (en) * | 2005-09-15 | 2007-03-15 | Sharp Laboratories Of America, Inc. | Method and system of assigning priority to detection messages |
US20080212559A1 (en) * | 2007-01-26 | 2008-09-04 | Kumar Mahesh | Wireless proximity estimation |
US7487351B2 (en) | 2003-03-26 | 2009-02-03 | Panasonic Corporation | Data use management system, transmitting apparatus having management function, and data use management method |
US20090310574A1 (en) * | 2007-02-02 | 2009-12-17 | Beom Jin Jeon | Method for transmitting a data packet and a method of allocating a channel in a wireless network |
-
2010
- 2010-01-15 JP JP2010006750A patent/JP2011146970A/en not_active Withdrawn
- 2010-12-09 US US12/964,041 patent/US8959342B2/en not_active Expired - Fee Related
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7058414B1 (en) * | 2000-05-26 | 2006-06-06 | Freescale Semiconductor, Inc. | Method and system for enabling device functions based on distance information |
US7487351B2 (en) | 2003-03-26 | 2009-02-03 | Panasonic Corporation | Data use management system, transmitting apparatus having management function, and data use management method |
US20070058559A1 (en) * | 2005-09-15 | 2007-03-15 | Sharp Laboratories Of America, Inc. | Method and system of assigning priority to detection messages |
US20080212559A1 (en) * | 2007-01-26 | 2008-09-04 | Kumar Mahesh | Wireless proximity estimation |
US20090310574A1 (en) * | 2007-02-02 | 2009-12-17 | Beom Jin Jeon | Method for transmitting a data packet and a method of allocating a channel in a wireless network |
Also Published As
Publication number | Publication date |
---|---|
JP2011146970A (en) | 2011-07-28 |
US20110179276A1 (en) | 2011-07-21 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US7797755B2 (en) | Method to secure the transfer of a data stream, corresponding computer program product, storage means and nodes | |
US7287282B2 (en) | Copyright protection system, transmitter, receiver, bridge device, copyright protective method, medium, and program | |
US9231847B2 (en) | Apparatus and method for processing packet for routing and verifying path in domains | |
US20110179497A1 (en) | Data transmission and reception control apparatus, and data transmission and reception system, method, and program | |
US8649519B2 (en) | Method and apparatus for secure distribution of digital content | |
EP2166727B1 (en) | Center apparatus, terminal apparatus, and authentication system | |
US20150172064A1 (en) | Method and relay device for cryptographic communication | |
KR20160095201A (en) | Methods, systems, and media for providing access control for a computing device | |
EP3259897B1 (en) | Authenticating a browser-less data streaming device to a network with an external browser | |
CN102065323A (en) | Content distribution management device | |
US11159329B2 (en) | Collaborative operating system | |
US9961078B2 (en) | Network system comprising a security management server and a home network, and method for including a device in the network system | |
CN109981680B (en) | Access control implementation method and device, computer equipment and storage medium | |
WO2017005163A1 (en) | Wireless communication-based security authentication device | |
CN110519764B (en) | Security verification method, system, computer device and medium of communication device | |
KR20030019340A (en) | Method and apparatus for secure transmission of data | |
WO2016004905A1 (en) | Information transmission method, information reception method and apparatus | |
US8959342B2 (en) | Communication apparatus | |
KR20180113688A (en) | Encryption method and system using authorization key of device | |
US9298903B2 (en) | Prevention of password leakage with single sign on in conjunction with command line interfaces | |
US20110252439A1 (en) | Method for providing multimedia streaming service and related wireless packet relay apparatus and wireless set-top box | |
US20100275023A1 (en) | Transmitter, receiver, and content transmitting and receiving method | |
CN105744321A (en) | Broadcasting receiving apparatus and method for controlling thereof | |
US20100121966A1 (en) | Repeater and repeating method thereof | |
JP2007049468A (en) | Device and method for transmitting data |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: ALPINE ELECTRONICS, INC., JAPAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:HATAKEYAMA, HIDEYUKI;REEL/FRAME:025624/0837 Effective date: 20101203 |
|
STCF | Information on status: patent grant |
Free format text: PATENTED CASE |
|
MAFP | Maintenance fee payment |
Free format text: PAYMENT OF MAINTENANCE FEE, 4TH YEAR, LARGE ENTITY (ORIGINAL EVENT CODE: M1551) Year of fee payment: 4 |
|
FEPP | Fee payment procedure |
Free format text: MAINTENANCE FEE REMINDER MAILED (ORIGINAL EVENT CODE: REM.); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY |
|
LAPS | Lapse for failure to pay maintenance fees |
Free format text: PATENT EXPIRED FOR FAILURE TO PAY MAINTENANCE FEES (ORIGINAL EVENT CODE: EXP.); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY |
|
STCH | Information on status: patent discontinuation |
Free format text: PATENT EXPIRED DUE TO NONPAYMENT OF MAINTENANCE FEES UNDER 37 CFR 1.362 |
|
FP | Lapsed due to failure to pay maintenance fee |
Effective date: 20230217 |